The hydrotreatment of some aromatic amines was studied at temperatures ranging from 400 to 450°C and PH2=1 atm under flow conditions. Hydrogenolysis of aromatic amines involves direct cleavage of the C(sp2)N bond without saturation of the aromatic ring. The presence of hydrogen sulphide in the reaction stream has a promotional effect on the hydrogenolysis of C(sp3)N bond and an inhibitive effect on the hydrogenolysis of C(sp2)N bond. The use of a saturated hydrocarbon as diluent facilitates CN bond hydrogenolysis in the presence of hydrogen, irrespective of the carbon being sp2 or sp3 hybridized. © 1989.